1. Field of the Invention
The present invention relates to an air conditioner for a vehicle, and more particularly, to a rear air conditioner, which is installed at a rear side of a vehicle and supplies conditioned air to a rear seat area of a passenger compartment of the vehicle.
2. Description of the Related Art
In general, heaters induce high temperature cooling water from an engine to a heater core, heat air flowing around the heater core using the cooling water induced to the heater core to produce warm air, and supply the produced warm air to a passenger compartment of a vehicle.
Japanese Patent Laid-Open Publication No. 2000-283576 discloses an air conditioning system having a rear air conditioner for cooling and heating a rear seat area of a passenger compartment of a vehicle.
Rear air conditioners are installed at a rear side of a vehicle and cool and heat a rear seat area of a passenger compartment of the vehicle. The rear air conditioners may be manufactured as a type only for generating cold air and a type only for generating warm air according to requirements of vehicle makers. In recent years, the rear air conditioners are manufactured as an air mixing type in which cold air and warm air are mixed to provide a more comfortable atmosphere to users.
In the air mixing type rear air conditioners, a heater core and an evaporator core are properly arranged such that warm air and cold air respectively provided by the heater core and the evaporator core can be mixed to produce mixed air at an optimum temperature and the mixed air can be supplied to a desired outlet port through a vent duct or a floor duct according to a user's operation.
In the meantime, when it comes to a layout of the rear air conditioners, the rear air conditioners are under many restrictions due to the shape of the vehicle, that is, due to vehicle parts (e.g., a wheel base and a rear lamp) installed in the rear seat area. Since it is difficult to properly arrange the heater core and the evaporator core in the limited area, the temperature control performance of the rear air conditioners to eliminate horizontal and vertical differences of room temperature may be degraded.
FIG. 1 is a schematic partial sectional view of a rear seat of a vehicle provided with a conventional rear air conditioner 1. FIG. 1 illustrates just a rear side of the vehicle. The conventional rear air conditioner 1 is mounted on a side of a vehicle body 3. The conventional rear air conditioner 1 thermally exchanges blown from a blower 11 to control temperature. The air controlled by the rear air conditioner 1 is discharged toward a passenger's head through a rear vent outlet port 13 or toward the passenger's feet through a rear floor outlet port 14.
FIG. 2 is a schematic sectional view of the rear air conditioner shown in FIG. 1.
Referring to FIG. 2, the rear air conditioner 1 for the vehicle includes a case 10, a heat exchanger 21 for cooling, a heat exchanger 22 for heating, an air passage 23, and a mixing room 24.
The case 10 includes an inlet port 12 through which air enters from the blower 11, the vent outlet port 13, and the floor outlet port 14. The heat exchanger 21 cools the inlet air and produces cold air 23a. The heat exchanger 22 heats the cold air 23a and produces warm air 22a. The air passage 23 is a path through which air passing through the heat exchanger 21 for cooling enters the mixing room 24. The mixing room 24 permits the cold air 23a and the warm air 22a to be mixed therein.
The rear air conditioner 1 can discharge mixed air through the vent outlet port 13 and the floor outlet port 14. The mixed air is produced after the cold air 23a and the warm air 22a are mixed in the mixing room 24.
However, as shown in FIG. 2, the cold air 23a and the warm air 22a are not sufficiently mixed in the mixing room 24, such that most of the cold air 23a is discharged through the floor outlet port 14, and most of the warm air 22a is supplied through the vent outlet port 13.
In the meanwhile, when the rear air conditioner 1 supplies the mixed air, the rear air conditioner 1 generally should provide relatively warm air to the passenger's feet and relatively cold air to the passenger's head by making the temperature of the mixed air discharged through the floor outlet port 14 higher than the temperature of the mixed air discharged through the vent outlet port 13, so as to provide a comfortable atmosphere to the passenger.
However, in reality, the rear air conditioner 1 supplies relatively cold air to the floor outlet port 14, which is directed toward the passenger's feet, and relatively warm air to the vent outlet port 13, which is directed toward the passenger's head, due to the arrangement of the heat exchangers in the limited area that the floor outlet port is disposed near to the heat exchanger for cooling, thereby failing to provide a comfortable atmosphere to the passenger.
Accordingly, the conventional rear air conditioner 1 does not demonstrate satisfactory performance to control a vertical difference of temperature, which means a temperature difference between the floor outlet port and the vent outlet port, to users when it supplies the mixed air.
On the other side, Japanese Patent Laid-Open Publication No. 1999-348533 discloses a front air conditioner, in which air passages for bypassing air flowing under a heat exchanger for heating toward a defrost vent are installed on both sides of a case to increase the temperature of air emitted from a defrost orifice and ensure smooth defrosting.